Can'r run program, error message!

I've this problem while I was about to open MS.Access.
At that moment, there was only 1 other program running : Visual Studio 2008,
then this error message pop up

Code:

The system DLL user32.dll was relocated in memory. The application will not run
roperly. The relocation occurred because the DLL C:\WINDOWS\system32\SHELL32.dll
occupied an address range reserved for Windows system DLLs. The vendor supplying
the DLL should be contacted for a new DLL.

After I close the visual studio 2008 and try to run Ms.Access,
it was still pop again.